Duotone

Reprints the photo in two inks. The darkest parts take the first, the brightest take the second, and everything between is a mix.

Start from a preset – each one is a real pair of inks. Cyanotype and Van Dyke are photographic processes, blue or brown on rag paper; Riso, Two-Pass and Overprint are screen-printing inks. Amount fades it back toward your photo, and Balance decides which ink claims the midtones.

Black and white film is the classic partner.

Advanced

Path changes the route between the two inks without moving the inks themselves. In the middle it takes the straight line, which is what two opposite inks do when they overprint on a real press – often a muddy grey. Push it either way and the midtones travel through a different color instead, warm one way and cool the other. The slider is painted with what it does.

Preserve keeps your photo’s own contrast. At zero the inks’ brightness rules, which is flat and graphic and right for a cyanotype – a real one never reaches black. Turn it up and the photo’s contrast comes back with only the color replaced.

The two inks sit below. Tap one to edit its Hue, Chroma and Lightness; the swatch shows what the press will lay down.